【作者】 韩昆仑；

【导师】 蔡泽祥；

【作者基本信息】 华南理工大学 ， 电力系统及其自动化， 2013， 博士

【摘要】 高压直流输电系统由于在输电距离、传输容量以及经济性上具有显著的优势，目前在跨区域电网间的互联与大容量远距离输电中获得广泛应用。换流器与直流输电线路是高压直流输电系统的核心元件，其故障特征和保护组成最具直流系统特征，与交流系统继电保护存在较明显的差异，对于整个直流输电系统的安全稳定运行具有重要的影响。本文以直流输电系统的换流器和直流输电线路这两个典型元件作为研究对象，针对直流保护普遍存在的动作行为不确定性、缺乏系统的整定计算方法及定量分析手段等问题开展研究。本文首先建立了面向直流保护的直流输电系统故障分析模型。针对换流器保护在换流器交流连接线故障时的动作行为存在不确定性的问题，研究了换流器保护各特征量的动态特性和动作判据，分析了交流连接线上故障位置、故障类型及系统运行方式对保护动作行为的影响，明确了换流器保护对交流连接线故障响应的规律，为换流器保护优化提供了依据。本文提出了基于保护特征量分析直流继电保护动作行为的方法。研究了直流线路保护特征量的动态特性，分析了故障条件（包括本极线路故障、对极线路故障、平波电抗器阀侧故障以及交流母线故障）、系统运行方式（包括单极大地方式、单极金属回线方式以及双极方式）和直流控制作用对直流线路故障暂态及保护特征量的影响规律，明确了直流线路各保护判据的动作边界、约束条件和功能定位，为直流线路保护优化与整定计算提供了依据。本文进一步提出了适用于直流线路各保护的统一整定计算方法，研究了保护装置采样率对直流线路保护整定影响的特殊问题，分析了直流线路各保护灵敏度系数影响因素与取值原则，有效解决了目前直流保护依据经验进行整定且缺乏有效的定量分析方法与手段的难题，将直流保护整定纳入到了电力系统继电保护整定的整体框架之中。基于以上理论，本文开发了直流线路保护整定计算程序，实现了直流线路保护的整定计算、定值校核、数据分析以及文档输出等功能。结合我国多个直流输电工程实际参数与保护配置进行了整定计算，验证了本文方法与程序的正确性与有效性。该整定计算程序已在实际直流输电工程中获得应用。本文工作得到国家高技术研究发展计划（“863”计划）（项目编号：2012AA050209）的资助，部分研究成果已经在电网运行部门的实际工作中得到应用，验证了本文工作的正确性和有效性，取得了良好的社会和经济效益。更多还原

【Abstract】 HVDC is today being widely used to connect regional power grids and transmit bulkpower to distant locations since they have more advantages in the aspects of transmissionability and economic benefit compared to HVAC. Converter and dc line are the two corecomponents of HVDC systems. They characterize the HVDC system well in fault analysisand protection principle, and their performance determines the reliability and efficiency of thewhole HVDC system. Therefore, we focus on the two components in this paper. Of thespecial importance are: the uncertain behavior of HVDC protective relaying and the lack ofefficient method for setting determination and performance evaluation.This paper proposes a fault analysis model for the research of protective relaying. Thebehavior of the converter protective relay is uncertain when faults occur on the link betweenthe converter and transformer. To solve the problem, we analyze the relaying quantitycharacteristics and protection criterion function of the converter protective relaying, in whichthe effect of fault location, fault type and operation condition of HVDC system are fullyconsidered. The study results clarify the response of the protective relay to the faults on thelink between the converter and transformer, which in turn gives a basis for the optimization ofconverter protective relaying.This paper proposes a method for the behavior analysis of HVDC protective relayingbased on the relaying quantity studies. The method is used to study the behavior of dc lineprotective relays. The dynamic characteristics of the relaying quantities are firstly studiedconsidering the effect of fault condition, system operation condition, and control systembehavior. The fault condition contains faults on the concerned pole and on the other pole,faults on the converter side of the smoothing reactor, and faults on the commutation bus. Theoperation condition contains bipolar operation, monopolar metallic return operation, andmonopolar ground return operation. The study results clarify the boundary, constraintcondition, and function of the protection criterions, which in turn gives a basis for the settingdetermination and optimization of dc line protective relaying.This paper also proposes a unified method for the setting determination of various dc line protections. The principle of selecting protection thresholds is proposed and the protectionsensitivity is fully analyzed considering various factors. A special attention is given to theproblem that the sampling frequency will affect the threshold settings of dc line protections.By doing so, we effectively solve the problem of lacking efficient method for the settingdetermination and performance evaluation of dc line protections, and incorporate the probleminto the framework of conventional power system protection.Based on the proposed theories, this paper finally develops a setting determinationprogram for dc line protections. The program can be applied to threshold selection, thresholdevaluation and electrical quantity analysis, etc. The program has been used in several actualHVDC projects. The performance verifies the correctness and validation of the theoriesproposed in this paper.This work is supported by the National High Technology Research and DevelopmentProgram (“863” Program) of China (No.2012AA050209). Some of the research results havebeen applied to the operation of actual HVDC systems, obtaining great economic and socialbenefit.更多还原